# create an user function term with an SQL::Statement object as owner,
# specifying the function name, the subroutine name (full qualified)
# and the parameters to the subroutine
my $term = SQL::Statement::Function::UserFunc->new( $owner, $name, $sub, \@params );
# access the result of that operation
$term->value( $eval );

# create an user function term with an SQL::Statement object as owner,
# specifying the expression to evaluate and the parameters to the subroutine
my $term = SQL::Statement::NumericEval->new( $owner, $expr, \@params );
# access the result of that operation
$term->value( $eval );

# create an trim function term with an SQL::Statement object as owner,
# specifying the spec, char and the parameters to the subroutine
my $term = SQL::Statement::Trim->new( $owner, $spec, $char, \@params );
# access the result of that operation
$term->value( $eval );

# create an substr function term with an SQL::Statement object as owner,
# specifying the start and length of the sub string to extract from the
# first element of \@params
my $term = SQL::Statement::SubString->new( $owner, $start, $length, \@params );
# access the result of that operation
$term->value( $eval );

# create an substr function term with an SQL::Statement object as owner
# and \@params to concatenate
my $term = SQL::Statement::StrConcat->new( $owner, \@params );
# access the result of that operation
$term->value( $eval );